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Bio

Clinical Focus

  • Gastroenterology
  • Neurogastroenterology and Motility Disorders
  • Gastroparesis

Academic Appointments

Boards, Advisory Committees, Professional Organizations

  • Member, American Neurogastroenterology & Motility Society (2016 - Present)
  • Member, American Gastroenterology Association (AGA) (2015 - Present)

Professional Education

  • Board Certification: American Board of Internal Medicine, Gastroenterology (2019)
  • Fellowship: Stanford University Gastroenterology Fellowship (2018) CA
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2017)
  • Residency: New York Presbyterian Cornell Campus Internal Medicine Residency (2015) NY
  • Medical Education: Weill Cornell Medical College (2013) NY

Contact

  • Stanford Digestive Health Clinic 420 Broadway St Pavilion D 2nd Fl Redwood City, CA 94063
    • Tel: (650) 736-5555
    Fax: (650) 498-5692
  • Stanford Gastroenterology and Digestive Health Clinic 450 Broadway St Pav D 2nd Fl Pod 2 and 3 Redwood City, CA 94063
    • Tel: (650) 736-5555
    Fax: (650) 498-6323

Research & Scholarship

Clinical Trials

  • GI-Challenge Study for Gastroparesis Patients and Healthy Controls Recruiting

    Gastroparesis Patients and Healthy Controls ages 20-49 will be asked to participate in an observational study measuring vagal activity following food ingestion in order to establish parameters of autonomic nerve/vagal function in healthy human subjects compared to those with gastroparesis. Information generated from this study may be used in the future to establish what is normal and abnormal enteric vagal tone and how much vagal nerve stimulation treatment may be required to help patients with gastroparesis.

    View full details

  • Vagal Nerve Stimulation for Gastroparesis Recruiting

    This study is investigating a new form of treatment for a digestive disorder called gastroparesis. Gastroparesis is thought to be caused by a mix of inflammation and neural dysfunction. The vagal nerve is a large nerve originating from the brain that regulates digestive function. Patients with gastroparesis have what is a called a low vagal tone which results in gastrointestinal motility problems and inflammation; therefore, investigators hypothesize that increasing vagal tone through a hand-held vagal nerve simulator will reduce inflammation and gastrointestinal motility problems in gastroparesis patients. Investigators will evaluate this hypothesis through the use of upper endoscopy testing, breath testing, and blood, stool, urine, heart rate variability, and saliva testing before and after 4 weeks of vagal nerve stimulation (VNS) treatment. There are 6 research visits Visit 1 and visit 2 may take up to 8 weeks (screening/baseline) Visit 3 and visit 4 will take 4 weeks (VNS treatment) visit 5 and 6 will take approximately 4 weeks (VNS followup/washout) Consequently, it is possible that if a patient were to be at the farthest ends of visit windows, they could potentially be in the study for approx 16 weeks. Visit 1 and 2 may be less than 8 weeks which would shorten the patient's overall involvement in the study. The treatment phase of the study will always be 4 weeks with an additional 4 week washout phase. Use of the VNS device takes 4 weeks. Endoscopy and blood work are taken before and after the treatment period.

    View full details

Publications

All Publications

  • Serotonin is elevated in COVID-19-associated diarrhoea. Gut Ha, S., Jin, B., Clemmensen, B., Park, P., Mahboob, S., Gladwill, V., Lovely, F. M., Gottfried-Blackmore, A., Habtezion, A., Verma, S., Ro, S. 2021

    View details for DOI 10.1136/gutjnl-2020-323542

    View details for PubMedID 33402416

  • Effects of processing conditions on stability of immune analytes in human blood. Scientific reports Gottfried-Blackmore, A., Rubin, S. J., Bai, L., Aluko, S., Yang, Y., Park, W., Habtezion, A. 2020; 10 (1): 17328

    Abstract

    Minimizing variability in collection and processing of human blood samples for research remains a challenge. Delaying plasma or serum isolation after phlebotomy (processing delay) can cause perturbations of numerous analytes. Thus, a comprehensive understanding of how processing delay affects major endpoints used in human immunology research is necessary. Therefore, we studied how processing delay affects commonly measured cytokines and immune cell populations. We hypothesized that short-term time delays inherent to human research in serum and plasma processing impact commonly studied immunological analytes. Blood from healthy donors was subjected to processing delays commonly encountered in sample collection, and then assayed by 62-plex Luminex panel, 40-parameter mass cytometry panel, and 540,000 transcript expression microarray. Variance for immunological analytes was estimated using each individual's baseline as a control. In general, short-term processing delay led to small changes in plasma and serum cytokines (range-10.8 to 43.5%), markers and frequencies of peripheral blood mononuclear cell phenotypes (range 0.19 to 3.54 fold), and whole blood gene expression (stable for>20K genes)-with several exceptions described herein. Importantly, we built an open-access web application allowing investigators to estimate the degree of variance expected from processing delay for measurements of interest based on the data reported here.

    View details for DOI 10.1038/s41598-020-74274-8

    View details for PubMedID 33060628

  • Noninvasive vagal nerve stimulation for gastroenterology pain disorders. Pain management Gottfried-Blackmore, A., Habtezion, A., Nguyen, L. 2020

    Abstract

    Abdominal pain continues to be a major challenge and unmet need in clinical practice. Normalization of bidirectional gut-brain signaling has generated much interest as a therapeutic approach to treat chronic abdominal pain. Vagal nerve stimulation (VNS) is emerging as a potential non-pharmacologic strategy for the treatment of abdominal pain. In this review paper, we will summarize the etiologies of chronic pain in gastrointestinal disorders and discuss the rational for VNS as a therapeutic approach to chronic abdominal pain, with particular emphasis in the gammaCore stimulator which allows for noninvasive VNS.

    View details for DOI 10.2217/pmt-2020-0067

    View details for PubMedID 33111642

  • Open-label pilot study: Non-invasive vagal nerve stimulation improves symptoms and gastric emptying in patients with idiopathic gastroparesis. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society Gottfried-Blackmore, A., Adler, E. P., Fernandez-Becker, N., Clarke, J., Habtezion, A., Nguyen, L. 2019: e13769

    Abstract

    BACKGROUND: Gastroparesis, a chronic motility disorder characterized by delayed gastric emptying, abdominal pain, nausea, and vomiting, remains largely unexplained. Medical therapy is limited, reflecting the complex physiology of gastric sensorimotor function. Vagus nerve stimulation is an attractive therapeutic modality for gastroparesis, but prior methods required invasive surgery. In this open-label pilot study, we aimed to assess the benefit of non-invasive vagal nerve stimulation in patients with mild to moderate idiopathic gastroparesis.METHODS: Patients self-administered the gammaCore vagal nerve stimulator for 4weeks. The gastroparesis cardinal symptom index daily diary (GCSI-dd) was assessed during a two-week run-in period, ?4weeks of therapy, and 4weeks after therapy was completed. Gastric emptying and autonomic function testing were also performed. The primary endpoint was an absolute reduction in CGSI-dd of 0.75 after nVNS.RESULTS: There was a total improvement in symptom scores (2.56±0.76 to 1.87±1.05; P=.01), with 6/15 (40%) participants meeting our primary endpoint. Therapy was associated with a reduction in gastric emptying (T1/2 155 vs 129minutes; P=.053, CI -0.4 to 45). Therapy did not correct autonomic function abnormalities, but was associated with modulation of reflex parasympathetic activity.CONCLUSIONS: Short-term non-invasive vagal nerve stimulation led to improved cardinal symptoms and accelerated gastric emptying in a subset of patients with idiopathic gastroparesis. Responders had more severe gastric delay at baseline and clinical improvement correlated with duration of therapy, but not with improvements in gastric emptying. Larger randomized sham-controlled trials of greater duration are needed to confirm the results of this pilot study.

    View details for DOI 10.1111/nmo.13769

    View details for PubMedID 31802596

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